OSPAR started in 1972 with the Oslo Convention against dumping. It was broadened to cover land-based sources and the offshore industry by the Paris Convention of 1974. These two conventions were unified, updated and extended by the 1992 OSPAR Convention.
Many man-made and naturally-occurring chemicals end up in the North-East Atlantic as a result of land-based and sea-based human activities. Some of these chemicals are hazardous for the marine environment.
The OSPAR Hazardous Substances Strategy sets the objective of preventing pollution of the maritime area by continuously reducing discharges, emissions and losses of hazardous substances; with the ultimate aim of achieving concentrations in the marine environment near background values for naturally-occurring substances and close to zero for man-made synthetic substances.
For OSPAR purposes, hazardous substances are defined as substances that are persistent, toxic (PBT substances) and liable to bioaccumulate, or that give rise to an equivalent level of concern as the PBT substances. This might, for example, be concern that they can interfere with the hormone system of organisms.
The OSPAR Commission has put in place a number of measures to reduce discharges from the oil and gas industry. Chemical suppliers (including lubricants) must provide the national authorities with data and information about chemicals to be used and discharged offshore according to the Harmonised Offshore Chemical Notification Format (HOCNF). Based on the information sent by the chemical supplier, the national authorities carry out pre-screening and environmental ranking of chemicals.
This highlights chemicals that do not meet the environmental criteria and need to be phased out from use or that are banned from discharge. This information is then used by operators to select products with the best environmental performance.
The OSPAR guidelines use three primary criteria to determine the level of impact of chemicals and hazardous substances in the marine environment:
Marine toxicity is a measure of the toxic effect of a chemical/product on marine organisms. To ensure that the effect on all elements of the marine environment is established, testing is carried out on four different types of organism (representing four different levels of the marine food chain):
Marine toxicity is measured by establishing the concentration of the substance that kills 50% of a population in a given period. Example: LC50 (96hr)=50ppm means a 50ppm concentration of a substance kills 50% or more of the organisms under test after an exposure period of 96 hours.
The higher the test result, the better (i.e. a result of 50ppm is better than 5ppm). The OSPAR pass level for organic substances is LC50<10mg/l.
Marine biodegradation (test method OECD 306) is a measure of how readily a substance is broken down by biological activity within the marine environment. It is classified by the percentage of the substance that is biodegraded within a specified time period (generally 28 days) under controlled conditions.
A substance that does not biodegrade at all during this period has 0% biodegradability; one that biodegrades completely has 100% biodegradability. High-percentage biodegradability is desirable, ideally >60% biodegradation in 28 days or >20% if the substances is non-bioaccumulative and non-toxic.
Bioaccumulation method OECD 117 is a measure of the tendency of a substance to accumulate within the tissue of living organisms, and hence be transferred up to the food chain. It is classified by the preferential solubility of the substance in octanol compared to solubility in water – the log Pow (octanol/water) coefficient.
A substance with a coefficient of 0 does not bioaccumulate; one with a coefficient of 6 has a high tendency to bioaccumulate. Substances with log Pow <3 are considered to be non-bioaccumulative under OSPAR requirements. Molecules with a high molecular weight (>700) do not bioaccumulate as they are too large to enter gill or cell membranes.
For all four organisms, toxicity, biodegradation and bioaccumulation data must be considered for every discrete chemical component of a product, regardless of the level present. This ensures that high biodegradability and/or low bioaccumulation performance of a product does not disguise the presence of low levels of chemicals having very poor environmental performance (e.g. lubricant additives are often strongly surface-active and stable organic compounds, which means that they have a strong potential to be toxic and to bioaccumulate).
Classification of components within products – Pre-screening
OSPAR criteria are used to establish whether individual components used in a product are acceptable or substitutable.
In summary, substances are classified as one of the following:
Inorganic substances with acute toxicity (EC50 or LC50 <1mg/l)
Organic substances with a biodegradability of BOD28 <20%
Substances that meet two of the three following criteria:
biodegradability <60 % in 28 days
bioaccumulation potential log Pow >3
acute toxicity LC50 or EC50 <10mg/l
Substitutable chemicals are required to be phased out of products, leading to the reformulation and recertification of products. This may require operators to change the products that they are using.